Ah lovely thanks but is there anything for how to wire up an LED to a battery or voltage source and just test each segment, calculate the required voltage source and resistor, just a basic intro to seven segment LED's that explains the basics?

Ah lovely thanks but is there anything for how to wire up an LED to a batter or voltage source and just test each segment, calculate the required voltage source and resistor, just a basic intro to seven segment LED's that explains the basics?

Usually, all of the LEDs are pretty much the same in a seven-segment display. If you want to test each LED, though, you can. It looks like the people that made you "datasheet" skimped on a lot, they didn't even label anode or cathode!

If you connect the cathode and anode incorrectly, you shouldn't have a problem as the LED will be reversed biased, not allowing current to flow through it(unless you are using a fairly high voltage. I'm assuming you are using 5V or less...). You should try to connect the anode to +5V and attach the cathode to ground through a 1kΩ resistor.

What this means for you, to test 'a', is that you should connect pin 3 and/or pin 8 to +5V and pin 7 through a 1kΩ resistor. You should see 'a' light up. If not, then it may be a common cathode device, meaning you'll need to connect pin 3 and/or pin 8 to ground and pin 7 to +5V through a 1kΩ resistor. Once the LED is lit, measure the forward voltage of the diode. Then you can calculate the resistance needed to get your desired amperage...

Ok great thanks Ill give it a go when I get home and see what happens. That "datasheet" can't even be called a real datasheet, not sure what they were thinking. All the other parts have serial numbers so at least you can search for a real datasheet but the one i need doesnt even have a serial number which is weird.

Btw regarding anodes and cathodes, as pins 3 and 8 are common annodes I assumed the rest of the pins were common cathodes, is this not correct?

Btw regarding anodes and cathodes, as pins 3 and 8 are common annodes I assumed the rest of the pins were common cathodes, is this not correct?

Click to expand...

I put that disclaimer because the datasheet says A(C) which, to me, means that it may be a common anode or a common cathode pin.

The fact that there are other pins to the LEDs, means that they can't be common anything... There will usually be a common cathode, to ground, or common anode, to Vdd. This reduces the number of pins you need to hookup the device....